1. Field of the Invention
The present invention relates to a biometric information measuring apparatus and a biometric information measuring system for measuring biometric information, such as arterial oxygen saturation and heart rate.
2. Description of the Related Art
A pulse oximeter is a device often used in diagnosing sleep apnea syndrome (SAS) or chronic obstructive pulmonary disease (COPD), for instance. The pulse oximeter has a sensor unit which is attached to a specified body part of a subject. The sensor unit emits light toward the body part and detects part of the light reflected from or passing through the body part. The pulse oximeter is configured to measure blood oxygen saturation (SpO2) based on the amount of light detected by the sensor unit.
When connected to a personal computer in which a specific program is installed, the pulse oximeter can communicate therewith. In this case, the personal computer receives data on oxygen saturation during sleep for one night from the pulse oximeter attached to the subject and calculates changes in the oxygen saturation and the severity of sleep apnea in terms of oxygen desaturation index (ODI) which is defined as an average number of oxygen desaturation episodes per unit time of sleep obtained by averaging the received data.
Japanese Unexamined Patent Publication No. 2005-538784 describes an arrangement for measuring and monitoring the state of a cardiovascular system of a subject by using an electrocardiogram (ECG) measuring configuration. According to the Publication, the ECG measuring configuration transmits measurement data on the state of the cardiovascular system together with information on the location of the subject determined by use of the Global Positioning System (GPS) to a medical expert.
Generally, a biometric state of a human being monitored varies depending on his or her behavior and location, such as whether the subject is currently sleeping, bathing or walking, for instance. Therefore, it would be possible to analyze biometric information more exactly if the behavior and location of the subject at the time of measurement are known.